Machine frame, especially for piston compressors and piston steam engines



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Helnmt Blawdszun Heinz Tacoby H. BLAUDSZUN ETAL 3,3@2,537 MACHINE FRAME, ESPECIALLY FOR PISTON COMPRESSORS fieb. 7, 1967 AND PISTON STEAM ENGINES Filed May 29, 1964 5 Sheets-Sheet Z5 imam/W5 Hem-mi Blqudszan Heinz Tacoby H. BLAUDSZUN ETAL 3,32,537 MACHINE FRAME, ESPECIALLY FOR PISTON COMPRESSORS AND PISTON STEAM ENGINES Feb. 7, 1967 5 Sheets-Sheet 4 Filed May 29, 1964 Jnvenfars; Helmut 'BLcuwLszun Heinz -Taco by Feb. 7, 1967 H. BLAUDSZUN ETAL 3,392,537

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United States Patent O MACHINE FRAME, ESPECIALLY FOR PISTON ODMPRESSORS AND PISTON STEAM ENGINES Helmnt Blaudszun and Heinz Jacoby, both of Berlin,

Germany, assignors to Borsig Aktiengesellschaft, Berlin, Germany Filed May 29, 1964, Ser. No. 371,214 4 Claims. (Cl. 92-261) The present invention concerns a machine frame, especially for piston compressors and piston engines of the opposed cylinder type, in which standard two-crank engine frame units are employed for two or more crank engines.

With heretofore known designs of the above mentioned type, it is standard procedure with two and more crank engines to make each the crank housing and the oil pan of one cast piece to which are connected by bolts or the like across head guides for each individual cross head. Thus, with the heretofore known constructions of the type involved, the cross head guides form separate parts whereby a considerable additional work is involved in the manufacturing process. Also, dynamic forces are guided through the connection between the crank housing and the crosshead guiding means whereby the sealing is made considerably more difficult. Moreover, in order to assure the necessary rigidity of the crank housing-oil pan unit, relatively expensive and large constructions are necessary which additionally require tie-rods and supports above the bearings in order to prevent the crank case from spreading on both sides of the restrictions for the bearings.

A further drawback of the heretofore known machine frames of the type involved consists in that the power flow between the shaft bearings and the intermediate members establishing the connection between the machine frame and the cylinders undergoes a sudden deviation in view of the sudden merging of the rather slender cross head guiding parts with the bulky crank case. These sudden deviations of the power flow may cause disorders. Furthermore, it is to be noted that with the heretofore known engines of the above-mentioned type having one or more pairs or cranks of about the same piston stroke and about the same rod forces per pair of cranks, a separate mold of a different design is necessary for each engine respectively having one, two, three or more pairs of cranks to which as an extension of the two crosshead guiding means there are flanged one intermediate member each and a cylinder or cylinder group.

It is, therefore, an object of the present invention to provide a machine frame, especially for piston compressors and piston steam engines of opposed cylinder type, which will overcome the abovementioned drawbacks.

It is another object of this invention to provide a machine frame, especially for piston compressors and piston steam engines of the opposed cylinder type, which will make it possible by using one and the same machine frame type, selectively to accommodate machines with one, two, three and more pairs of cranks by combining two or more of said frames.

It is another object of this invention to provide a machine frame as set forth in the preceding paragraphs, which will assure an improved power flow in the frame construction.

It is also an object of this invention to provide a machine frame unit of the character set forth in the preceding paragraphs, which will be torsion-resistant and non-sensitive against vibrations.

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawings, in which:

FIG. 1 is a longitudinal section through a frame housing 3,302,537 Patented Feb. 7, 1967 a two-crank shaft with the connecting rods pertaining thereto.

FIG. 2 is a longitudinal section through the machine frame of FIG. 1 with the parts therein omitted, said section being taken along the line IIII of FIG. 1.

FIG. 3 represents a section taken along the line IIIIII of FIG. 2.

FIG. 4 is a section taken along the line IV1V of FIG. 2.

FIG. 5 diagrammatically illustrates a single frame unit according to the present invention indicating in full lines the frame unit as it is to be used for engines with one pair of cranks only and indicating in dot-dash lines an additional integral component of the frame unit when it is intended to compose a plurality of units to an engine frame for engines with a plurality of pairs of cranks.

FIGS. 6 and 7 respectively diagrammatically illustrate the combination of two frame units of FIG. 5 with the dotdash line component included respectively making up the housing for two different engines.

FIG. 8 diagrammatically illustrates the combination of three frame units to accommodate still another modified engine, each of said frame units likewise corresponding to that of FIG. 5 with the component indicated by dot-dash lines.

FIG. 9 diagrammatically illustrates a machine frame unit with a bearing portion cast thereonto.

FIG. 10 is a combination of a frame unit of FIG. 9 with a frame unit of FIG. 5 including the component indicated by dot-dash lines in FIG. 5.

FIGS. 11 and 12 respectively illustrate inner and outer flange connections for interconnecting adjacent machine frame units.

FIG. 13 shows sheet metal plates for use in connection with the present invention which are arranged in a labyrinth-like manner for establishing a pressure equalization and protecting the interior of a machine frame against the entry of soil and the like.

The machine frame according to the present invention is characterized primarily in that it forms a single integral cast unit while having a crank housing section, an oil pan section, two slide path sections and two cross head guiding sections.

Referring now to the drawings in detail and FIGS. 1 to 4 thereof in particular, the machine frame unit 1 comprises a crank housing section 2, an oil pan section 5, two slide path sections 6 and two cross head guiding sections 8. The crank housing section 2 receives the pair of cranks 15 with the crank webs 17 and the respective connecting rods 21 and cross head bearings 23.

Each cross head guiding section 8 (FIG. 4) comprises two slide bearing races 9 and the ribs 10 between said bearing races and the housing 6 and the oil return portions 35. The machine frame unit 1 represents in its horizontal central section substantially a rectangle with two diagonally oppositely located slanted wall portions arranged parallel to each other. As will be seen in particular from FIGS. 1, 2 and 3, the machine frame unit 1 represents a girder-like construction comprising four angle-shaped arms 38, two collars 39, two drip edges 40 in crank case 2, two oil pan ribs 41 and two slide path housings 6 with the slide races 9, ribs 10, oil returns 35, longitudinal legs 36 and transverse legs 37 cast thereon. The said girder-like construction is particularly torsionresistant in view of the great equatorial inertia moments thereof for the cross-sectional shapes perpendicular to the sliding path axis 33. As a result thereof, and, more specifically, in view of the high natural frequency re-.

sulting from the said girder-like construction, the latter is non-sensitive against vibrations. It will, therefore, be appreciated that in spite of the fact that a machine frame unit of the present invention meets the requirement of being well resistant against torsion, machine frame structures composed of one or more machine frame units of the present invention have a considerably lower weight than corresponding machine frames of heretofore known machines in which the same rod forces and piston strokes prevail. The machine frame unit, according to the present invention forms a structure with smooth main power flow directions 25 without any material or intervening deviations as will be greatly evident from FIGS. 1 to 4. This is due to the location of the angle-shaped arms 38 (FIG. 3), the drip edges 40 between the shaft bearings 19, and the four upper corners 2a and four lower corners 2b of the crank housing 2. The advantageous design of the machine frame according to the invention is furthermore due to the gradual merging of the cross-section of the upper slide path housing portion 6 with the upper connecting flange semicircle of the intermediate member 13, 13a. As will be seen from FIG. 1, the central section of the slide path housing 6 has a trapezoidal contour, one side of said trapezoidal cross-section extending from the crankcase 2 to the intermediate section 13, 1311 while tapering toward the latter, whereas two other sides of said trapezoidal cross-section are parallel to the bearing axis 34. The fourth side of said trapezoidal crosssection is parallel to the slide path axis 33. The advantageous design of the machine frame according to the invention is furthermore due to the cast-in slide path races 9, ribs 10, oil returns 35, and longitudinal leg portions 36.

The arrangement and dimensioning of the angularshaped arms 38, the drip edges 40 within the machine frame unit 1, and the provision of strong girder-like parts extending from the shaft bearings to all eight corners of the crank housing proper, and furthermore, the extension of the four girder sections to the four lower corners and their design as oil returns 35 which slightly taper toward the crank shaft within the slide path housing portions, will safely prevent a spreading of the crank housing 2 at both sides of the restrictions for the bearings 4. As a result thereof, tie-rods or additional supports above the said restrictions, will be superfluous (FIGS. 1 to 4). The dynamic loads will be absorbed without difficulty by the cast body. Any slight bending apart of the said restrictions when the machine is in operation is irrelevant and will be safely absorbed by the housing lid 3.

The slide path housing 6 and the cross-head guiding means 8 are so arranged that when looking in the direction of the slide path axis 33, relatively large, free crosssections 11 (FIGS. 1 and 4) will be obtained between the cross-head 24 and the slide path housing 6. This brings about a considerable reduction in the pumping effect of the cross-head 24 and piston rod 26, even at the highest speeds of the crankshaft. This, in turn, results in a likewise considerable reduction in oil losses through the gap between piston rod 26 and the wiping ring 27 in the intermediate section 13, 13a.

Furthermore, according to the present invention, the lids for the particularly large assembling windows 7 are provided in the slide path housing 6 with pressure equalizing openings 12. As will be seen from the drawing, some of said assembling windows 7 are inclined with regard to the slide path axis. The said openings 12 are confined by labyrinth-shaped sheet metal parts (FIG. 13) which protect the interior of the machine frame unit 1 against the access of soil. In addition to bringing about a pressure equalization, they also vent the interior of the machine frame unit when the lubricating oil changes its temperature during operation and the standstill of the machine. Finally, the said openings reduce the pumping effect of cross-head 24 and piston rod 26 as well as the oil losses through the gap between piston rod 26 and wiper 27.

When it is desired to compose a plurality of machine frame units of the type referred to above with 4, 6 or more cylinders in order to build up frames for machines with a plurality of pairs of cranks, the machine frame units 1 may, in conformity with the specific requirements, be provided with corresponding cast-on portions 29. The cast-on portions 29 may, of course, have different lengths 29a in conformity with the necessary cylinder diameters and the variable distances 28 between two adjacent cylinders. These cast-on portions 29 will, of course, be provided with means such as flanges 32 (FIGS. 6, 11 and 12) or the like, which will make it possible firmly to interconnect the respective frame units.

It will also be obvious from the drawings that the cast-on portions 29 may be provided at either end of the frame unit whereby it is possible to vary the distances 28a and 28b between two adjacent cylinders (see FIGS. 6 and 7). In conformity with standard procedures, there is provided a main model which is then combined with corresponding model sections depending on the variable length sections 29a to be connected to the frame unit. It will thus be obvious that a certain machine frame unit 1, 1a is suitable for the construction of machines with one or a plurality of pairs of cranks provided that the said machines have the same piston stroke and approximately the same rod forces occur per crank pair 15. By providing a series of types of machine frame units of considerably dififerent piston stroke and adapted to absorb considerable differences in load per crank pair, it is possible to build a wide range of machines of different volumina and outputs.

With machines having two, four, six pairs of cranks 15, it is possible completely to balance the moments which act upon the foundation in view of the inertia forces of the vibrating parts. Thus, a complete equalization of the masses can be obtained by respectively building up and assembling the machine frame units 1, 1a in pairs so that one unit 1 forms the image of the other unit In (FIG. 7).

When machine frame units are to be built which have to support a rotor arranged in overhanging position and pertaining to an electric machine, supplement sections with built-in special shaft bearings may be provided in conformity with FIG. 9. To this end, machine frame unit 1, 1a is provided with a cast-on bearing section 30 comprising a built-in shaft bearing 20 for supporting an overhanging rotor 31 of an electric motor. This would be required, for instance, when employing a machine frame unit for a piston compressor. Similarly, such caston portion could be employed for an overhanging generator rotor of a piston steam engine whereby crank shaft 14 will not be subjected to additional stresses by the weight of the rotor.

When building up machines with two or more pairs of cranks, each two adjacent machine frame units 1, 1a may be interconnected, for instance, by outer or inner flanges 32 or by cementing the sections to each other (FIGS. 6 to 8 and 10) which are located outside the effective range of the dynamic forces. As cement in this connection may be employed, for instance, Wevo-MK (WevO-Gesellschaft, Chemische F abrik, Stuttgart).

The shaft studs 16 and crank studs 18 may be journalled in pre-fabricated shaft bearings 19 and crank stud bearings 22. In this way, expensive assembly work Wlll be saved but in this connection it is, of course, necessary that the slide path axes 33 are precisely perpendicular to the bearing axis 34.

As will be evident from the above, a machine frame unit according to the present invention represents a girder-like construction which is torsion-resistant and thus also non-sensitive against vibration which are caused by dynamic forces. Furthermore, the power flow in the frame units according to the present invention occurs along substantially straight lines through strong elements along the cross-head guiding means.

It is, of course, to be understood that the present invention is, by no means, limited to the particular constructions and arrangements shown in the drawings, but also comprises any modifications Within the scope of the appended claims.

What we claim is:

1. A machine housing structure for opposed cylinder type engines, especially piston compressors and steam engines, which consists of a single unitary cast piece having a crank housing section for receiving crankshaft means having only one pair of cranks, an oil pan section, two slide path housing sections respectively located on opposite sides of said crank housing section, and two cross-head guiding sections respectively located on opposite sides of said crank housing section and in alignment with respective ones of said cranks, the horizontal central section of said housing structure substantially having the contour of a rectangle with two diagonally oppositely located corners respectively cut olf by two substantially parallel lines, said housing structure having its crank housing section provided with two pairs of arms with the arms of each pair forming an upright V with each other while flaring toward the top portion of said housing structure, said crank housing section also being provided with two flange portions at the top portion of said housing structure and with two drip edges at substantially the level at which the apex of said V is located, said oil pan section being provided with ribs forming an inverted V with each other, each of said slide path housing sections being provided with ribs extending in the longitudinal direction of said housing structure and also being provided with substantially vertical and horizontal leg portions, whereby the housing structure unit forms a girder-like construction.

2. A machine housing structure according to claim 1, which includes rib means leading from said slide path housing sections to said oil pan sections and forming oil return passages while simultaneously stifiening the housing structure.

3. A machine housing structure according to claim 2, in which said crank housing section is provided with hearing means and has restrictions therefor, and in which said arms and said drip edges and said oil return forming ribs are so dimensioned as to prevent any substantial spreading of the crank housing section at both sides of the restrictions for said bearing means.

4. A machine housing structure for opposed cylinder type engines, especially piston compressors, which consists of a single unitary cast piece having a crank housing section for receiving crank shaft means having only one pair of cranks, crank shaft bearing means arranged in said crank housing section, said housing structure in the form of a single unitary cast piece also comprising an oil pan section and two slide path housing sections respectively located on opposite sides of said crank housing section and furthermore comprising two cross-head guiding sections respectively located on opposite sides of said crank housing section and in alignment with respective ones of said cranks, said crank housing section being provided with two pairs of arms with the arms of each pair forming an upright V with each other while flaring toward the top portion of said housing structure, said crank housing section also being provided with two flange portions at the top portion of said housing structure and with two drip edges at substantially the level at which the apex of said V is located, said crank housing section having four upper and four lower corner portions, said arms and said drip edges respectively being located between said crank shaft bearing means and the four upper corner and four lower corner portions of said crank housing section, said housing structure also including merging sections gradually merging the upper portion of said slide path housing sections with said crank housing section whereby a smooth main power flow of the forces exerted upon said housing structure will be assured, the horizontal section through each of said slide path housing sections being of a trapezoidal contour with two sides parallel to the axes of said bearing means with one side parallel to the axis of said slide path housing section and with one side tapering from said crank housing section toward the outer end of said slide path housing section.

References Cited by the Examiner UNITED STATES PATENTS 1,577,006 3/1926 Watts 123-195 1,977,075 10/1934 Magnuson 92169 2,079,357 5/1937 Morris et a1 92-147 2,443,830 6/ 1948 McDaniel 29-1564 2,491,630 12/ 1949 Voorhies 123-195 2,739,574 3/ 1956 Schieterlein 92 147 2,852,837 9/1958 Fageol 29156.4 2,914,045 11/1959 Hill.

3,229,591 1/1966 Cadiou 12341.86

FOREIGN PATENTS 1,119,942 6/1956 France.

MARTIN P. SCHWADRON, Primary Examiner. SAMUEL LEVINE, Examiner. 

1. A MACHINE HOUSING STRUCTURE FOR OPPOSED CYLINDER TYPE ENGINES, ESPECIALLY PISTON COMPRESSORS AND STEAM ENGINES, WHICH CONSISTS OF A SINGLE UNITARY CAST PIECE HAVING A CRANK HOUSING SECTION FOR RECEIVING CRANKSHAFT MEANS HAVING ONLY ONE PAIR OF CRANKS, AN OIL PAN SECTION, TWO SLIDE PATH HOUSING SECTIONS RESPECTIVELY LOCATED ON OPPOSITE SIDES OF SAID CRANK HOUSING SECTION, AND TWO CROSS-HEAD GUIDING SECTIONS RESPECTIVELY LOCATED ON OPPOSITE SIDES OF SAID CRANK HOUSING SECTION AND IN ALIGNMENT WITH RESPECTIVE ONES OF SAID CRANKS, THE HORIZONTAL CENTRAL SECTION OF SAID HOUSING STRUCTURE SUBSTANTIALLY HAVING THE CONTOUR OF A RECTANGLE WITH TWO DIAGONALLY OPPOSITELY LOCATED CORNERS RESPECTIVELY CUT OFF BY TWO SUBSTANTIALLY PARALLEL LINES, SAID HOUSING STRUCTURE HAVING ITS CRANK HOUSING SECTION PROVIDED WITH TWO PAIRS OF ARMS WITH THE ARMS OF EACH PAIR FORMING AN UPRIGHT V WITH EACH OTHER WHILE FLARING TOWARD THE TOP PORTION OF SAID HOUSING STRUCTURE, SAID CRANK HOUSING SECTION ALSO BEING PROVIDED WITH TWO FLANGE PORTIONS AT THE TOP PORTION OF SAID HOUSING STRUCTURE AND WITH TWO DRIP EDGES AT SUBSTANTIALLY THE LEVEL AT WHICH THE APEX OF SAID V IS LOCATED, SAID OIL PAN SECTION BEING PROVIDED WITH RIBS FORMING AN INVERTED V WITH EACH OTHER, EACH OF SAID SLIDE PATH HOUSING SECTIONS BEING PROVIDED WITH RIBS EXTENDING IN THE LONGITUDINAL DIRECTION OF SAID HOUSING STRUCTURE AND ALSO BEING PROVIDED WITH SUBSTANTIALLY VERTICAL AND HORIZONTAL LEG PORTIONS, WHEREBY THE HOUSING STRUCTURE UNIT FORMS A GIRDER-LIKE CONSTRUCTION. 